3-carbamylpyrazolone azo compounds



United States Patent 3,282,913 S-CARBAMYLPYRAZOLONE AZO COMPOS MiltonGreen, Newton Centre, Mass, assignor to Polaroid Corporation, Cambridge,Mass, a corporation of Delaware N0 Drawing. Filed Aug. 9, 1963, Ser. No.301,197 11 Claims. (Cl. 260-163) This invention relates to photographyand more particularly to novel chemical compounds for use in products,compositions and processes for the development of photo sensitive silverhalide elements.

This application is in part a continuation of my copending applicationSerial No. 130,468, filed August 1961, now abandoned. The photographicutilization of the novel compounds of the present invention is claimedin my copending application Serial No. 301,181, filed concurrentlyherewith, now U.S. Patent 3,141,772, issued July 21, 1964.

A principal object of this invention is to provide novel chemicalcompounds.

Another object of this invention is to provide novel syntheses forpreparing the novel compounds of the present invention.

Another object of the present invention is to provide novel processesand compositions for the development of silver halide emulsions, inWhich colored developing agents are used to develop a latent image.

Another object is to provide novel processes and compositions for thedevelopment of silver halide emulsions, in which the novel developingagent is capable of developing a latent image and imparting a reversedor positive colored image of said latent image to a superposedimagereceiving material.

A further object is to provide novel products, processes andcompositions suitable for use in preparing monochromatic andmultichromatic photographic images.

Other objects of the invention will in part be obvious and will in partappear hereinafter.

The invention accordingly comprises the processes involving the severalsteps and the relation and order of one or more of such steps withrespect to each of the others, and the products and compositionspossessing the features, properties and the relation of elements whichare exemplified in the following detailed disclosure, and the scope ofthe application of which will be indicated in the claims.

For a fuller understanding of the nature and objects of the invention,reference should be had to the following detailed description.

The novel photographic developing agents employed in this inventionpossess the properties of both a dye and a developing agent; thus theymay be referred to as dye developers. The nature of these dye developerswill be described hereinafter.

The photographic processes and compositions disclosed I herein areparticularly useful in the treatment of an exposed silver halideemulsion, whereby a positive dye image may be imparted to anotherelement, herein referred to as an image-carrying or image-receivingelement.

U.S. Patent No. 2,983,606, issued May 9, 1961, to Howard G. Rogers,discloses diffusion transfer processes wherein a photographic negativematerial, such as a photographic element comprising an exposed silverhalide emulsion is developed in the presence of a dye developer toimpart to an image-receiving layer a reversed or positive dye image ofthe developed image by permeating into said emulsion layer a suitableliquid processing composition and bringing said emulsion layer intosuperposed relationship with an approprate image-receiving layer.

It is an object of this invention to provide additional dye developerssuitable for use in such processes.

Patented Nov. 1, 1965 In carrying out the process of this invention, aphotosensitive element containing a silver halide emulsion is exposedand wetted with a liquid processing composition, for example, byimmersing, coating, spraying, flowing, etc., in the dark, and thephotosensitive element superposed, prior to, during or after wetting, onan image-receiving element. In a preferred embodiment, thephotosensitive element contains a layer of dye developer, and the liquidprocessing composition is applied to the photosensitive element in auniform layer as the photosensitive element is brought into superposedposition with an imagereceiving element. The liquid processingcomposition permeates the emulsion to provide a solution of dyedeveloper substantially uniformly distributed therein. As the exposedsilver halide emulsion is developed, the oxidation product of the dyedeveloper is immobilized or precipitated in situ with the developedsilver, thereby providing an imagewise distribution of unoxidized dyedeveloper dissolved in the liquid processing composition. Thisimmobilization is apparently, at least in part, due to a change in thesolubility characteristics of the dye developer upon oxidation, andespecially as regards its solubility in alkaline solutions. It also maybe due, in part, to a tanning eiiect on the emulsion by the oxidizeddeveloping agent. At least part of this imagewise distribution ofunoxidized dye developer is transferred, by imbibition, to a superposedimage-receiving layer. Under certain circumstances, the layer of theliquid processing composition may be utilized as the image-receivinglayer. The imagereoeivin'g layer receives a depthwise diffusion, fromthe emulsion, of unoxidized dye developer, without appreciablydisturbing the itnagewise distribution thereof, to provide a reversed orpositive, colored imme of the developed image. The image-receivin gelement may contain agents adapted to mordant or otherwise fix thediiiused, unoxidize d dye developer. If the color of the diffused dyedeveloper is affected by changes in the pH of the image-receivingelement, this pH may be adjusted in accordance with well-knowntechniques to provide a pH affording the desired color. Imbi-bitionperiods of approximately one miuute have been found to give goodresults, but this contact period may be adjusted where necessary tocompensate for variations in temperature or other conditions. Thedesired positive image is revealed by stripping the imagereceivingelement from the photosensitive element at the end of the imbibitionperiod.

The dye developers of this invention may be utilized in thephotosensitive element, for example in, on or behind the silver halideemulsion, or they may be utilized in the image-receiving element or inthe liquid processing composition. In a preferred embodiment, a coatingor layer of the dye developer is place-d behind the silver halideemulsion, i.e., on the side of the emulsion adapted to be located mostdistant from the photographed subject when the emulsion is exposed andpreferably also adapted to be most distant from the image-receivingelement when in superposed relationship therewith. Placing the dyedeveloper behind the emulsion layer, as in the preferred embodiment, hasthe advantage of providing increased contrast in the positive image, andalso minimizes any light-filtering action by the colored dye developer.In this preferred embodiment, the layer of dye developer may be appliedby using a coating solution containing about 0.5 to 8%, by weight, ofthe dye developer. Similar concentrations may be used if the dyedeveloper is utilized as a component of the liquid processingcomposition. In an especially useful mode of dispersing the dyedevelopers in the photosensitive elements, the dye developer isdissolved in a water-immiscible solvent and then dispersed in a gelatincoating solution.

The liquid processing composition above referred to comprises at leastan aqueous solution of an alkaline com- -29 pound, for example,diethylamine, sodium hydroxide or sodium carbonate, and may contain thedye developer. In some instances, it may contain a minor amount of aconventional developing agent. If the liquid processing composition isto be applied to the emulsion by being spread thereon, preferably in arelatively thin, uniform layer, it may also include aviscosity-increasing compound constituting the film-forming material ofthe type which, when said composition is spread and dried, will form arelatively firm and relatively stable film. A preferred film-formingmaterial is a high molecular weight polymer such as a polymeric,water-soluble ether inert to an alkali solution, as for example, ahy-droxyethyl cellulose or sodium carboxymethyl cellulose. Otherfilmforming materials or thickening agents whose ability to increaseviscosity is substantially unaflected when left in solution for a longperiod of time may also be used.

The novel chemical compounds of the present invention may be representedby the formula:

wherein Q is the radical of a diazotizable amine, Ar is a phenyleneradical, M is a lower alkylene radical, n is an integer from to 1,inclusive, Y is an orthoor para-dihydroxyphenyl radical and alkyl andhalogen derivatives thereof, R and R each may be hydrogen or an alkylradical, and R and R together may be a divalent aliphatic radical, e.g.,a pentamethylene radical completing, with the nitrogen atom, apiperidine ring. Preferably R and R contain no more than 10 to 12carbons. It should also be understood that the term alkyl, asrepresented by R and R is intended to include substituted alkylradicals, e.g., hydroxyalkyl radicals.

Q, the diazotizable amine, is preferably a primary amine of the benzeneor naphthalene series. The radical, Q, thus may be represented by theformula:

wherein Q is a phenyl or naphthyl group, X is a hydrogen, halogen, loweralkyl, lower a'lhoxy, sulfonamido or trifluoromethyl radical, and Xbeing located ortho to said N=N group, R is a lower alkoxy, halogen,lower alkyl, trifluoromethyl or sulfonamido radical, and p is an integerfrom 0 to 4, inclusive.

In a preferred embodiment, Q is a substituted phenyl group, n is 1, andY is a para-dihydroxphenyl radical. Such compounds may be represented bythe formula:

I OH

wherein R p, X, R R and M have tthe same meaning as above.

As examples of alkylene radicals comprehended by the radical M, mentionmay be made of radicals such as -CH CH and CH -CH CH The preferredembodiment is a lower alkylene group, e.g., less than 6 carbons, andmore preferably an ethylene group. It should be understood that M may bean alkylene group comprising 6 or more carbon atoms provided that theresulting dye developer is capable of being dissolved in the liquidprocessing composition, and its oxidation product rendered immobile.

As noted above, Q may be derived from any amine which is capable ofdiazotization. When Q is a phenyl radical, in addition to the orthosubstituent X, the phenyl radical may also contain other substituents,above desig- 20 nated R in the 3, 4, 5 or 6 position or any combinationthereof. The particular substituent selected and its specific positionmay be determined by one skilled in the art guided by the teachings ofthe present invention and with due regard to the substituents effect onthe color, solubility and light stability of the compound.

As examples of substituents represented as R mention may be made ofmethyl, ethyl, chloro, methoxy, and ethylsulfonamido. It should beunderstood that R may be further substituted, if desired.

The copending application of Milton Green, Serial No. 268,451, filedJanuary 14, 1963, discloses and claims compounds within Formula Bwherein X and R are sulfonamido radicals.

3 As examles of novel chemicals within the scope of the presentinvention, mention may be made of the following:

=N -|-[-CONHC2H5 I G D-C (1)1-(4"-hydroquin-onylethylphenyl)-3-tN-ethylcarbamyl-4-(2-4-dimethylphenylazo -5-pyrazo1one 0 OH N=N Wi l-N 31H; HOlN O s-C (2)1-(4"-hydroquinonylethylphenyl)-3-(N-pentameth lene)- 7 carbamyl--(2,4,6-trimethylphenylazo) -5-pyrazo1 ne N 311 H N/ U CH3 C BHnCH OHmethylphenylazo) -5-pyrazol0ne t CH; =N 'Tv&NHCHzCHzCHzOH H HOlN OH2CH IOH N (5H3 N/ CHI OH;

I OH

I I! 1!! II/ III !II ilryhlthgl gili .i% hy;$?p1 ziarbfhtil ftl f ltltrifluorornethylphenylazo)-5-pyrazol0ne The dye developers disclosed andclaimed in the copending application of Milton Green, Serial No.301,198, filed concurrently herewith, when the radical in the 3-position is an ester, have been found to be susceptible to hydrolysis,during synthesis, of the o H CO-Z radical in the 3-position of thepyrazolone ring, wherein Z is an alkyl radical. The corresponding freeacid is diflicult to separate from the corresponding ester, and thepresence of the free acid may detract from the usefulness of such dyedevelopers in some (but not all) photographic applications e.g., bygiving undesired transfer in diffusion transfer applications because ofthe greater solubility and mobility of the free acid than of thecorresponding ester.

It has now been found that the compounds of the present inventionwherein the carboxylate radical has been replaced by a carbamyl radicalretain many of the desirable properties of said dye developers butwithout the susceptibility to hydrolysis.

The dye developers of this invention, compared to the dye developers ofthis copending application of Milton Green, Serial No. 301,198, filedconcurrently herewith, wherein the radical in the 3-position is an esterradical, do not exhibit hydrolysis of the 3-carbamyl group duringsynthesis, e.g., during hydrolysis of the acylated Y radical duringsynthesis, or under the conditions present during photographicutilization. By the replacement of the ester group by an amide groupmany advantages of the dye developers of the copending application,e.g., improved silver halide developing properties and increased lightstability characteristics, have been retained while a seriousdisadvantage, i.e., the tendency of the ester group, particularly a3-carbethoxy group, to undergo hydrolysis during synthesis, has beeneliminated.

The novel chemical compounds of the present invention may be prepared byreplacement of the 3-carboxylate group with an amide group in a compoundof the formula:

QN=N Wil-o-z is the protected derivative, preferably the acylatedderivative. The term acyloxy is intended to signify the grouping whereinD is an aryl, alkyl, arloxy, or alkoxy group. The terms alkyl and arylas employed herein are intended to include substituted aryl and alkylgroups.

As examples of amines suitable for use in the present invention, mentionmay be made of alcoholic ammonia, primary amines, such as ethylamine,secondary amines, such as diethylamine, heterocyclic amines, such aspiperidine, hydrazines, hydroxylamines and guanidine.

The process for the preparation of the novel chemical compounds of thepresent invention is disclosed and claimed in the copending applicationof Milton Green, Serial No. 130,467, filed August 10, 1961, nowabandoned.

The following nonlimiting examples illustrate the preparation of dyedevelopers within the scope of this invention.

Example 1 A ml. stainless steel bomb containing 5.84 gm. (0.01 M) ofl-(4"-hydroquinonylphenethyl)-3-carbethoxy-4-(4-methylphenylazo)-5-pyrazolonewas chilled in a Dry Ice bath and flushed with nitrogen. 30 ml. ofethylamine were then added and the bomb was sealed and heated on thesteam bath overnight. The bomb was then cooled to below room temperatureand opened. The excess ethylamine was removed by passing a stream ofnitrogen through the reaction mixture. The temperature of the bomb wasmaintained at room temperature and deaerated dilute hydrochloric acidwas added. The resulting solid was filtered, washed with more dilutehydrochloric acid and dried with suction. The product, 1-(4"-hydroquinonylethylphenyl) 3 N ethyl carbambly- 4(2',4'-dimethylphenylazo)-5-pyrazolone, melted at 245 C. Withdecomposition and showed the following analysis calculated for C H N OCalculated: C, 67.4; H, 5.7; N, 14.0. Found: C, 67.2; H, 5.9; N, 13.6.

Eyample II 100 ml. of 40% methylamine were placed in a 250 ml. roundbottom flask, flushed with nitrogen for 5 minutes. 5.51 gm. (0.01 M) of1-(4"-hydroquinonylethylphenyl) 3 carbethoxy 4 (2',4',6t-rimethylphenylazo) 5 pyrazolone were added to the flask. The flask wasfitted with a condenser, and an adapter and a balloon were fitted to theopen end of the condenser. The mixture was left standing overnight. Theexcess methylamine was then boiled off on the steam bath. Deaerateddilute hydrochloric acid was added to the reaction mixture and theresulting solid was filtered, washed with dilute-hydrochloric acid andsucked dry. The product, 1-(4"-hydroquinonylethylphenyl) 3 N methylcarbamy 4- (2',4',6 trimethylphenylzo) 5 pyrazolone, melted at 206-7 C.with decomposition. The spectral absorption curve exhibited a X at 438mp; e=18,000.

Example 111 l (4" hydroquinonylethylphenyl) 3 carbethoxy- 4 (2,4',6trimethylphenylazo) 5 pyrazolone was treated with an excess ofdimethylamine for 16 hours at 90l00 C. The resulting product,l-(4"-hydroquinonylethylphenyl) 3 N,N dimethylcarbamyl 4 (2',4,6-trimethylphenylazo)-5-pyrazolone melted at 210-l1 C., withdecomposition. The spectral absorption curve showed a k at 415 mp;e=18,800.

Example IV 1 (4" hydroquinonylethylphenyl) 3 carbethoxy- 4 (2,4',6'trimethylphenylazo) 5 pyrazolone was heated with an excess of piperidinefor 16 hours at 90- 100 C. The resulting product, 1 (4"hyd-roquinonylethylphenyl) 3 (N pentamethylene) carbamyl 4-(2,4,6'-trimethy1phenylazo) 5 pyrazolone melted at 219-21 C. Thespectral absorption curve exhibited a A at 412 m e='19,000.

Example V 1 (4" hydroquinonylethylphenyl) 3 carbethoxy- 4 (2,4,6trimethylphenylazo) 5 pyrazolone was heated with alcoholic ammonia for16 hours at 90-100 C. The resulting product, 1 (4"hydroquinonylethylphenyl) 3 carbamyl 4 (2',4,6' trimethylphenylazo) 5pyrazolone, melted at 2015-2025 C. The spectral absorption curveexhibited a 7 at 440 mp; e=-17,400.

Example VI 1 (4" hydroquinonylethylphenyl) 3 N,N diethylcarbamyl 4(2',4',6 trirnethylphenylazo) 5 pyrazolone was prepared by treating 1(4" hydroquinonylethylphenyl) 3 carbethoxy 4 (2,4',6'trimethylphenylazo) 5 pyrazolone with an excess of diethylamine for 16hours at 90100 C.

Example VII 1 (p [2,5' diacetoxyphenylpropyl] phenyl) 3- carbethoxy 4(2',4',6 trimethylphenylazo) 5- pyrazolone was treated withmethylaminoethanol in a nitrogen atmosphere to provide 1 (4"hydroquinonyll6 propylphenyl) 3 (N ethyl N hydroxyethyl) carbamyl 4(2,4',6' trimethylphenylazo) 5 pyrazolone melting at 201-203 C. withdecomposition.

Example VIII 1 (p [2,5' diacetoxyphenylpropyl] phenyl) 3- carbethoxy 4(2',4',6' trimethylphenylazo) 5 pyrazolone was treated with3-amino-1-propanol at 95 C. to provide 1 (4" hydroqinonylpropyl) 3(nhydroxy-propyl) carbamyl 4 (2',4,6' trimethylphenylazo)-5-pyrazolone,melting at l62164 C.

Example IX 1 (p [2,5 diacetoxyphenethyl] phenyl) 3- carbethoxy 4 (2,4,6trimethylphenylazo) 5 pyrazolone was heated with an excess ofn-propylamine to provide (4" hydroquinonylethylphenyl) 3 Nnpropylcarboxamido 4 (2',4',6' trimethylphenylazo)- 5-pyrazolone,melting at -117 C.

Example X 1 (p [2,5 diacetoxyphenylpropyl] phenyl) 3- carbethoxy 4(2',4,6' trimethylphenylazo) 5 pyrazolone was heated in a nitrogenatmosphere with an excess of 2 amino 2 methyl 1,3 propanediol to provide1 (4' hydroquinonylpropylphenyl) 3 (N-{3,fi'- bishydroxymethyl) ethylcarbamyl 4 (2',4',6' trimethylphenylazo) 5 pyraxolone which melted at C.

Example XI 1 (p [2,5' diacetoxyphenethyl] phenyl) carbethoxy 4 (2,4',6'trimethylphenylazo) 5 pyrazolone was treated with l-amino-Z-propanol toprovide 1- (4" hydroquinonylethylphenyl) 3 (2' hydroqinonylethylphenyl)3 (2' hydroxypropyl) carbamyl 4- (2',4',6' trirnethylphenylazo) 5pyrazolone, melting at 206-207 C.

The dye developers of this invention are also useful in integralmultilayer photosensitive elements for use in multicolor difiusiontransfer process. As an example of such photosensitive elements, mentionmay be made of the photosensitive elements disclosed and claimed in thecopending US. application of Edwin H. Land and Howard G. Rogers, SerialNo. 565,135, filed February 13, 1956, wherein at least two selectivelysensitized photosensitive strata are superposed on a single support andare processed, simultaneously and without separation, with a singlecommon image-receiving element. A suitable arrangement of this typecomprises a support carrying a red-sensitive silverhalide emulsionstratum, a green-sensitive silver halide emulsion stratum and ablue-sensitive silver halide emulsion stratum, said emulsions havingassociated therewith, respectively, a cyan dye developer, a magenta dyedeveloper and a yellow dye developer. In one of the preferredembodiments of photosensitive elements of this type, the dye developersare disposed in separate alkali-permeable layers behind thephotosensitive silver halide emulsion stratum with which they areassociated.

The photosensitive elements within the scope of this invention may beused in roll film units which contain a plurality of photosensitiveframes. The photosensitive elements of this invention are especiallyuseful in composite roll film intended for use in a Polaroid LandCamera, or a similar camera structure such, for example, as the cameraforming the subject matter of US. Patent No. 2,435,717, issued to EdwinH. Land on February 10, 1948. In general, such composite roll filmscomprise a photosensitive roll, a roll of image-receiving material and aplurality of pods containing an aqueous alkaline processing solution.The rolls and pods are so associated with each other that, uponprocessing, the photosensitive element may be superposed on theimage-receiving element and the pods may be ruptured to spread theaqueous alkaline processing solution between the superposed elements.The nature and construction of the pods 17 used in such units are wellknown to the art. See, for example, US. Patents Nos. 2,543,181 and2,634,886, issued to Edwin H. Land.

It will be noted that the liquid processing composition may contain oneor more auxiliary or accelerating silver halide developing agents, suchas p-met-hylaminophenol (Metol); 2,4-diarninophenol (Arnidol);benzylaminophenyl; hydroquinone; a substituted hydroquinone such astoluhydroquinone, phenylhydroquinone, or 4-methylphenylhydroquinone; ora 3-pyrazolidone such as l-phenyl-3-pyrazolidone. These silver halidedeveloping agents are substantially colorless, at least in theirunoxidized form. It is possible that some of the dye developer oxidizedin exposed areas may be oxidized by an energy transfer reaction withoxidized auxiliary developing agent.

In addition, development may be elfected in the presence of an oniumcompound, particularly a quaternary ammonium compound, in accordancewith the processes disclosed and claimed in the copending US.application of Milton Green and Howard G. Rogers, Serial No. 50,- 851,filed August 22, 1960, and now US. Patent No. 3,173,786.

The dye developers of this invention may be used also in conventionalphotographic processes, such as tray or tank development of conventionalphotosensitive films, plates or papers to obtain black and white,monochromatic or toned prints or negatives, By way of example, adeveloper composition suitable for such use may comprise an aqueoussolution of approximately 1-2% of the dye developer, 1% sodiumhydroxide, 2% sodium sulfite and 0.05% potassium bromide. Afterdevelopment is completed, any unreacted dye developer is Washed out ofthe photosensitive element, preferably with an alkaline washing mediumor other medium in Which the unreacted dye developer is soluble. Theexpression toned is used to designate photographic images wherein thesilver is retained with the precipitated dye, whereas monochromatic isintended to designate dye images free of silver.

It should be noted that the dye developers of this medium are selfsufficient to provide the desired color image and do not depend uponcoupling reactions to produce the desired color. They thus provide acomplete departure from conventional photographic color processes inwhich the color is produced by a coupling reaction between a colorformer or coupler and the oxidized developing agent, as well asso-called auto-coupling processes in which color is obtained by areaction of the oxidized developing agent with unoxidized develoipngagent.

It will be apparent that, by appropriate selection of theimage-receiving element from among suitable known opaque and transparentmaterials, it is possible to obtain either a colored positive reflectionprint or a colored positive transparency. Likewise, the inventiveconcepts herein set forth are adaptable for multicolor work by the useof special photographic materials, for example, film materials of thetype containing two or more photosensitized elements associated with anappropriate number of imagereceiving elements and adapted to be treatedwith one or more liquid processing compositions, appropriate dyedevelopers suitable to impart the desired subtractive colors beingincorporated in the photosensitized elements or in the liquid processingcompositions. Examples of such photographic materials are disclosed inU.S. Patent No. 2,647,049 to Edwin H. Land.

As examples of useful image-receiving materials, mention may be made ofnylon, e.g., N-methoxymethylpolyhexamethylene adipamide, polyvinylalcohol, and gelatin, particularly polyvinyl alcohol or gelatincontaining a dye mordant such as poly-4-vinylpyridine. Theimage-receiving element also may contain a development restrainer, e.g.,1-phenyl-5-mercaptotetrazole, as disclosed in the copending applicationof Howard G. Rogers and Harriet W. Lutes, Serial No. 50,849, filedAugust 22, 1960.

The inventive concepts herein set forth are also adapt- 18 able for theformation of colored images in accordance with the photographic productsand processes described and claimed in U.S. Patent No. 2,968,559, issuedto Edwin H. Land on January 17, 1961.

The novel compounds herein disclosed are also suitable for use as dyesfor textile fibres, such as nylon.

In the preceding portions of the specification the expression color hasbeen frequently used. This expression is intended to include the use ofa plurality of colors to obtain black.

Since certain changes may be made in the above products, compositionsand processes Without departing from the scope of the invention hereininvolved, it is intended that all matter contained in the abovedescription shall be interpreted as illustrative and not in a limitingsense.

What is claimed is:

1. A compound of the formula:

wherein R is a radical selected from. the group consisting of loweralkyl, lower alkoxy, chlorine and trifluoromethyl radicals; p is aninteger from 0 to 4, inclusive; X is a radical selected from the groupconsisting of hydrogen, chlorine, lower alkyl, lower alkoxy, andtrifluoromethyl radicals, said X being located ortho to said N=N- group;Q is a radical selected from the group consisting of phenyl and naphthylradicals; Ar is a phenylene radical; M is a lower alkylene radical; n isan integer from 0 to 1, inclusive; Y is a radical selected from thegroup consisting of orthoand para-dihydroxyphenyl radicals and loweralkyl and chlorine derivatives thereof; and R and R each are selectedfrom the group consisting of hydrogen and lower alkyl radicals, and Rand R taken together may be a pentamethylene radical.

2. 1 (4 hydroquinonylethylphenyl)-3-N-ethylcarbamly-4- 2',5'-dimethylphenylazo -5-pyrazolone.

3. l-(4"-hydroquinonylethylphenyl) 3 (N pentamethylene)-carbamyl 4(2',4,6'-trimethylphenylazo)-5- pyrazolone.

4. 1-(4-hydroquinonylethylphenyl) 3 carboxamido- 4-2,4,6'-trimethylphenylazo -5-pyrazolone.

5. 1-(4"-hydroquinonylethylphenyl) 3 N,N-diethylcarbamyl-4-(2,4,6-trimethylphenylazo -5-pyrazolone.

6. 1-(4-hydroquinonylethylphenyl) 3 Nmethylcarbamyl-4-(2',4,6trimethylphenylazo)-5-pyraz0lone.

7. 1-(4"-hydroquinonylpropylphenyl) 3 (N hydroxypropyl)-carbamyl 4 (2trifluoromethylphenylazo)-5-pyrazolone.

8. 1 (4" hydroquinonylethylphenyl)-3-(N-hydroxypropyl)-carbamyl 4-(3trifluoromethylphenylazo)-5- pyrazolone,

9. l-(4"-hydroquinonylpropylphenyl) 3 (N hydroxypropyl)-carbamyl 4 (3trifiuoromethylphenylazo)-5-pyrazolone.

10. 1-(4"-hydroquinonylpropylphenyl) 3 (N hydroxypropyl)carbamyl-4-(2,4',6-trimethylphenylazo)- S-pyrazolone.

11. 1-(4"-hydroquinonylethylphenyl) 3 (N hydroxypropyl)carbamyl-4-(2',4,6-trirnethylphenylazo)- 5-pyrazolone.

References Cited by the Examiner FOREIGN PATENTS 554,935 8/1957 Belgium.

CHARLES B. PARKER, Primary Examiner.

F. D. HIGEL, Assistant Examiner.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 3 ,282,913 November 1, 1966 Milton Green It is hereby certified that errorappears in the above numbered patent requiring correction and that thesaid Letters Patent should read as corrected below.

Column 2, line 71, for "precessing" read processing column 3, line 49,for "and" read said column 4, line 35, for "examles" read examplescolumn 10, line 20, for "CF read CH column 12, line 67, for "OH" read C1column 13 line 15 for "4"' read 4- line 53, for "(3- trifluorometh-"read (3 -trifluorometh column 14, line 20, for "this" read said column15, line 10, for "carbam1'y" read carbamylline 16, for "Eyample" readExample line 29, for "carbamy" read carbamyl column 16, line 28, for"pyraxolone" read pyrazolone line 41, for "process" read processescolumn 18, lines 41 and 42, for "carbamly" read carbamyl Signed andsealed this 5th day of September 1967.

(SEAL) Attest:

ERNEST W. SWIDER EDWARD J. BRENNER Attesting Officer Commissioner ofPatents

1. A COMPOUND OF THE FORMULA: